Field
The disclosed technology relates to an organic electrolyte solution and lithium batteries using the same.
Description of the Related Technology
Lithium batteries can be used as driving power source for portable electronic devices such as video cameras, mobile phones, notebook computers, etc. Rechargeable lithium secondary batteries have at least 3 times higher energy density per unit weight than those of the conventional lead storage batteries, Ni—Cd batteries, Ni metal hydride (Ni-MH) batteries, Ni—Zn batteries and the like. In addition, the lithium batteries can be charged at high speed.
Since lithium batteries are operated at high voltage, they are not compatible with an aqueous electrolyte, which is highly reactive to lithium. Lithium batteries mostly use an organic electrolyte solution. An organic electrolyte solution is prepared by dissolving a lithium salt in an organic solvent. A suitable organic solution must be stable at high voltage, and have a high ion conductivity and dielectric constant, and also have a low viscosity.
When a carbonate-based polar non-aqueous solvent is used in lithium batteries, an irreversible reaction between the electrolyte solution and the positive or negative electrode may occur during an initial charging process, causing excess consumption of charges The irreversible side reaction leads to formation of a protection layer on the surface of a negative electrode. The protection layer prevents decomposition of an electrolyte solution during charging and discharging and also serves as an ion tunnel. A higher stability and a lower resistance of the protection layer can increase the life cycle of the lithium batteries, and also their stability while preventing change in volume. Therefore, there is a need for the development of an organic electrolyte solution which can form a protective layer with improved stability and low resistance.